1. Field of the Invention
The present invention relates to a solid state image device that can prevent color moire generation.
2. Description of the Related Art
An image receiving surface of a solid state imaging device, such as CMOS, CCD, CMD, BASIS, SIT, and so on is divided into a number of pixels. Light received at each pixel is converted into an electric signal. Each pixel is covered by one color filter of three primary color filters. An R (red) signal is generated by a pixel covered by a red color filter. A G (green) signal is generated by a pixel covered by a green color filter. A B (blue) signal is generated by a pixel covered by a blue color filter. A display surface of a monitor is divided into a number of display-blocks. A display-block, on the display surface, corresponds to a plurality of pixels, that are at the same relative location on the image receiving surface. The display-block is further divided into three emitting areas. Each emitting area emits R, G, or B light according to the RGB signals generated by the pixels.
A single pixel can generate one primary color signal, consequently the other primary color signals for the single display-block are interpolated from the signals generated by the pixels surrounding around single pixel. Due to color interpolation, color moire fringes are generated in areas, where spatial frequency is high. The color moire fringes result in an inaccurate picture being displayed on the monitor. Conventionally, generation of the color moire fringes is prevented by covering the image receiving surface with an optical-low pass filter, which limits the spatial frequency of the light reaching the imaging device.
On the other hand, an optical low-pass filter is expensive and large. Consequently, there are problems with decreasing the manufacturing cost of an imaging device and miniaturizing the imaging device.